Non-real Time Services

ABSTRACT

In certain embodiments, a method of receiving digital television signals involves tuning a radio frequency tuner to receive a radio frequency modulated channel containing a transport stream; demodulating the channel to produce an output transport stream; the output transport stream containing an Internet Protocol (IP) stream of packets containing non-real time content, a FLUTE file description table (FDT), NRT service metadata and NRT content metadata; demultiplexing the IP stream of packets to produce: NRT content that is stored in an electronic storage medium, the FLUTE FDT, NRT service metadata, and NRT content metadata; parsing the metadata to produces NRT service metadata; NRT content description text and NRT content metadata; and processing the NRT content description text derived from a Text Fragment Table (TFT). This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

CROSS REFERENCE TO RELATED DOCUMENTS

This application is a continuation of U.S. patent application Ser. No. 12/806,327 to Eyer filed Aug. 10, 2010 which is a continuation of U.S. patent application Ser. No. 12/584,171 filed Sep. 1, 2009 to Eyer now issued as U.S. Pat. No. 8,099,752, which is further related to and claims priority benefit of U.S. Provisional Patent Applications 61/200,767 filed Dec. 3, 2008, 61/200,981 filed Dec. 5, 2008, 61/206,049 filed Jan. 26, 2009 and 61/161,941 filed Mar. 20, 2009, all to Mark Eyer, and each of which is hereby incorporated herein by reference. Mark Eyer is also the author of a text entitled “PSIP: Program & System Information Protocol”, 2003, The McGraw Hill Companies, Inc. and terms, acronyms, etc. relating to PSIP and associated technologies used herein are consistent with their use in this text. The APPENDIX hereto forms a part of this specification and is hereby incorporated herein by reference.

COPYRIGHT AND TRADEMARK NOTICE

A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. Trademarks are the property of their respective owners.

BACKGROUND

Embodiments consistent with this invention pertain to non-real-time (NRT) video services for Advanced Television Systems Committee (ATSC) compliant digital terrestrial broadcasting. An NRT video service is one in which the audio/video content is streamed from the broadcaster to receiving devices at a slower rate or a faster rate (or a combination thereof) than real-time rate. Receiving devices utilize local storage to capture the streaming files so they can be made available to viewers upon arrival of a complete file, or playback can begin prior to complete download of the entire file.

NRT video services are presently available in a number of forms. For example, TiVo™ supports these today on the TiVo HD and TiVo Series 3 Personal Video Recorders using proprietary technology using the Internet as a distribution channel. However, there currently exists no standard way to implement these services for ATSC terrestrial broadcasts for playback on fixed television installations where Internet access is not available. Furthermore, the metadata associated with NRT services, including lists of available content and their descriptions would need to accompany the terrestrial broadcast even if the Internet could be used by the receiver to actually retrieve the files.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain illustrative embodiments illustrating organization and method of operation, together with objects and advantages may be best understood by reference detailed description that follows taken in conjunction with the accompanying drawings in which:

FIG. 1, is a diagram depicting delivery of IP packets via broadcast TV in a manner consistent with certain embodiments of the present invention.

FIG. 2 is a diagram depicting an example NRT Information Table and its interaction with other tables in a manner consistent with certain embodiments of the present invention.

FIG. 3 is an example block diagram of a digital television receiver with NRT reception capabilities consistent with certain embodiments of the present invention.

FIG. 4 is an example diagram of the table parsing used in a manner consistent with certain embodiments of the present invention.

DETAILED DESCRIPTION

While this invention is susceptible to embodiment in many different forms, there is shown in the drawings and will herein be described in detail specific embodiments, with the understanding that the present disclosure of such embodiments is to be considered as an example of the principles and not intended to limit the invention to the specific embodiments shown and described. In the description below, like reference numerals are used to describe the same, similar or corresponding parts in the several views of the drawings.

The terms “a” or “an”, as used herein, are defined as one or more than one. The term “plurality”, as used herein, is defined as two or more than two. The term “another”, as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e., open ended language). The term “coupled”, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. The term “program” or “computer program” or similar terms, as used herein, is defined as a sequence of instructions designed for execution on a computer system. A “program”, or “computer program”, may include a subroutine, a function, a procedure, an object method, an object implementation, in an executable application, an applet, a servlet, a source code, an object code, a shared library/dynamic load library and/or other sequence of instructions designed for execution on a computer system. The term “processor”, “controller”, “CPU”, “Computer” and the like as used herein encompasses both hard programmed, special purpose, general purpose and programmable devices and may encompass a plurality of such devices or a single device in either a distributed or centralized configuration without limitation.

The term “program”, as used herein, may also be used in a second context (the above definition being for the first context). In the second context, the term is used in the sense of a “television program”. In this context, the term is used to mean any coherent sequence of audio video content such as those which would be interpreted as and reported in an electronic program guide (EPG) as a single television program, without regard for whether the content is a movie, sporting event, segment of a multi-part series, news broadcast, etc. The term may also be interpreted to encompass commercial spots and other program-like content which may not be reported as a program in an electronic program guide.

Reference throughout this document to “one embodiment”, “certain embodiments”, “an embodiment”, “an example”, “an implementation” or similar terms means that a particular feature, structure, or characteristic described in connection with the embodiment, example or implementation is included in at least one embodiment, example or implementation of the present invention. Thus, the appearances of such phrases or in various places throughout this specification are not necessarily all referring to the same embodiment, example or implementation. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, examples or implementations without limitation.

The term “or” as used herein is to be interpreted as an inclusive or meaning any one or any combination. Therefore, “A, B or C” means “any of the following: A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive. Other terms used herein are consistent with their use in ATSC specifications and/or the above-referenced text by Mark Eyer unless otherwise defined or modified herein.

As previously noted, an NRT video service is one in which the audio/video content is streamed from the broadcaster to receiving devices at a slower rate or a faster rate (or a combination thereof) than real-time rate. Such services do not currently exist in a standardized format. Receiving devices utilize local storage to capture the streaming files so they can be made available to viewers upon arrival.

ATSC compliant digital television (DTV) broadcasts deliver 19.39 Mbps. transport streams which generally are not fully utilized every moment of the day. The excess capacity in these transport streams could be utilized for transporting NRT services. In some cases, the data may be sent in large bursts that are faster than real time, while in other instances, the data may be sent in smaller bursts or streams that are slower than real time. In either event, the content can be buffered to bulk storage in receivers for later presentation to a consumer. Generally, the present discussion enables the delivery and consumption of various types of NRT content. Some usage/consumption models that are envisioned include but are not limited to:

-   -   Browse and Download—the user is offered a list of content titles         available for download; he or she may browse through these and         select content items of interest. The files are automatically         fetched when available by the receiver and stored for the user         to view at a later time.     -   Push—a user subscribes to a “push” service which captures         certain content that is generally frequently updated (e.g.,         stock prices, weather reports, sports scores, etc.). The         receiver automatically fetches updates of the information; the         service appears to “push” the updated information to the user.     -   Portal—a TV channel appears in the form of a web site that can         be navigated by the user. Links on the TV channel generally lead         to locally stored content that is either in random access memory         (RAM) or persistent bulk storage.

In certain embodiments, a new ATSC Service Type for “NRT” is defined. The use of a new Service Type allows NRT services to be introduced into the digital broadcast television system in such a way that legacy receivers are unaffected—they disregard virtual channels with unknown Service Type values. While the Terrestrial Virtual Channel Table defines the service to be, in general, “Non-Real-Time,” the specific usage/consumption model for the NRT files is given in the Service Category field in the Service Map Table (SMT). In the future, more complex features and capabilities could be enabled by NRT methods, like targeted advertising, downloaded games, and the like. These services, if they were to be offered, would preferably employ different values of Service Category.

FIG. 1 depicts one mechanism through which broadcast television is utilized to implement IP multicast over an ATSC delivery transport in accord with ATSC standard A/92. In this figure, a Terrestrial Virtual Channel Table (TVCT per ATSC A/65) 2 provides information regarding each channel and includes a service type identifier of 8 (in this example) that defines the service as a NRT service that is delivered via IP packets. This table further provides TSID information and a program number that points to information in a Program Association Table (PAT) 4, which in turn points to a program map table (PMT) 6 via a program map PID (Packet Identifier). The PID is used to associate with a Digital Storage Media Command and Control (DSMCC) table 8 which essentially equates the content associated with the PID to an IP subnet to identify a data stream corresponding to the NRT data sought.

In accord with certain implementations consistent with the present invention, a standard method is provided to define a new table which is referred to herein as the NRT-IT (NRT Information Table). The NRT-IT table has unique structure and function which facilitates its use in organizing the metadata it conveys.

In addition, the NRT-IT table introduces several other novel metadata items relevant to the non-real-time application:

-   -   a parameter called Playback Delay, which indicates the amount of         time from the recovery of the first byte of the file the         receiver must wait prior to beginning playback of the content;     -   a method to indicate that a given piece of NRT content is         available also via Internet transport, and an indication of the         Uniform Resource Locator (URL) that can be used to retrieve it;     -   a flag indicating whether or not the NRT file can be extracted         from the broadcast stream with low-latency (while the user         waits), or whether the receiver should prompt the user to return         to view it at a later time (long latency). This latency may be         established according to a threshold that separates longer from         lower and may be determined by the broadcaster; and     -   a method to identify an graphical icon representation of the NRT         service or content item.

NRT content within the broadcast stream may be delivered in a discontinuous, non-uniform way, such that the rate of packets may be variable over time. A long movie file, for example, may be delivered at 50% of real-time speed for the first half of the file, and one-quarter real-time for the remainder. In this case, if a receiver were to extrapolate and guess that playback could commence when half the file had been buffered, playback would be interrupted because the slower rate in the second portion would cause buffer under-run. The Playback Delay parameter allows the receiver to avoid guessing by letting the broadcaster indicate when playback may safely start without causing the buffer to become empty during playback (assuming fast-forwarding does not occur).

In some prior NRT implementations (such as OMA BCAST—Open Mobile Alliance Broadcast), a Uniform Resource Indicator (URI) was associated with NRT content items, but receivers could not determine whether a given URI was also a URL (such that the content was also being made available via a server on the Internet). In a preferred embodiment of the present invention, the NRT-IT may associate a URL with content items that optionally may be retrieved by the Internet.

A data structure is defined which is referred to herein as a Internet Location Descriptor (ILD), which can be associated with one or more files carried in the broadcast multiplex to point to content that may be retrieved via the Internet, for the benefit of receivers that have Internet access. The ILD may appear in the NRT-IT, where it indicates the physical location of the file or files comprising the particular item of content available for download. The ILD may also be used within the PSIP Virtual Channel Table. In this location, the ILD points to multimedia content descriptive of the channel itself. Such content could include channel logo, HTML-formatted pages, etc.

This approach provides an efficient method to represent and transport the metadata used to describe NRT video services in a way that is compatible and complementary to existing practice in ATSC DTV transmission standards.

In the preferred embodiment of the present invention, a method originally defined for Internet Protocol (IP) transport over the Internet called “FLUTE” is employed. FLUTE, or “file delivery over unidirectional transport” is specified in RFC-3926. FLUTE builds on another IP-based transport method called Asynchronous Layered Coding, a base protocol that was designed for efficient distribution via IP-multicast methods. FLUTE defines a File Delivery Table (FDT) containing characteristics of one or more files contained in a “session.” The files delivered in a FLUTE session may be considered to be carried in a “carousel,” as the sequence of bytes comprising each file typically repeat cyclically.

As defined herein, the NRT-IT table has several attributes that distinguish it from an ATSC Data Event Table (DET) which is used in delivery of multicast sessions for ATSC Broadcasts. By way of example, some of the differences are:

-   -   NRT-IT gives first and last availability times for the content,         where the DET gives “start time” and “length,” highlighting the         fact that in the DET only real-time monitoring and use of the         data stream was contemplated.     -   NRT-IT gives playback time for stored content (the amount of         time it takes to play the complete file); this concept does not         appear in any of the ATSC data broadcast standards.     -   NRT-IT provides (via associated Internet Location         Descriptor—(previously referred to as Content Location         Descriptor in one or more of the above provisional         applications)) the location of one or more audio/video or other         content files within a transmitted FLUTE session.     -   NRT-IT provides the storage requirements for downloaded content;         DET does not.

The structure (syntax and semantics) of the NRT-IT is described below. This structure includes:

-   -   a) Extensions to existing methods for announcement of linear         broadcast television programming services to support         non-real-time delivery. Existing methods are based on the use of         ATSC A/65 PSIP. The extension defined here involves definition         of one new table, the NRT-IT (Non-Real Time Information Table),         and definition of new ATSC “Service Types.”     -   b) The existing standard ATSC descriptor mechanism is utilized,         and already standardized ATSC descriptors including the Caption         Services Descriptor, Content Advisory Descriptor, Genre         Descriptor, and ATSC and ISO Content Identifier Descriptor are         retained.     -   c) With the use of Content Identifier Descriptors in both the         NRT-IT and EIT, a user can easily search for NRT content         associated with any given live (real time) event advertised in         the EIT. Using this method, past episodes of the show currently         being watched can be scheduled for NRT download.

As mentioned, each defined Virtual Channel is associated with a Service Type. Typical Service Types are “ATSC Digital Television,” “Audio-Only Service,” and “Software Download.” The definition of the NRT Service Type embodies:

-   -   a. The fact that the Virtual Channel is a gateway to one or more         NRT services, in which the user is offered a number of content         items available for immediate or later download.     -   b. Each content item is described by a content title, a         descriptive sentence or paragraph, and other metadata (such as         content advisory, the availability of closed captioning,         optionally a JPEG image for on-screen representation of the         content item, etc.).     -   c. A defined set of audio/video codecs, transport encodings and         bindings; if the receiver supports this set, all NRT content         associated with this service will be renderable.     -   d. Each Virtual Channel of Service Type “NRT” has a pointer to a         set of entries in a Service Map Table (SMT). Each NRT service in         the SMT is associated with entries in an NRT Information Table         (NRT-IT), each instance of which describes a set of content         items the broadcaster has scheduled to be available for         download.

The definition of the syntax and semantics of the NRT-IT can take many forms, but in one example, the syntax and semantics are provided in the APPENDIX hereto. The APPENDIX, at several locations, uses the term TBD to mean To Be Determined. TBD values are a matter of choice which can be readily made by one skilled in the art upon consideration of the present teachings to provide standardization and can be selected to avoid conflicts.

Turning now to FIG. 2, an example NRT-IT is depicted as 10. The NRT-IT is linked to the SMT-MH table 12 by the service ID (e.g., SID 1). The SMT-MH table 12 is linked to a FLUTE File Delivery Table (FDT) 14 via the destination IP address and port number and Transport Session Indicator (TSI) value. Content identifier fields in the NRT-IT 10 reference files in the FLUTE FDT 14. One content identifier reference in the NRT-IT may reference one or more files in the FDT. A different content identifier, in the SMT 12, may be present to reference a file in the FDT containing a graphical icon that can be used to represent the service.

The FLUTE FDT is an IP packet-based directory of files that includes a content identifier that identifies content present in IP packets elsewhere in the IP packet stream. The content identifier also may link to an analogous field in a Text Fragment Table TFT 16 (formerly referred to as the extended text table in one or more of the above provisional applications) that provides textual metadata associated with the content. Thus, the files that represent NRT content and associated metadata is packaged as IP packets that are embedded within the broadcaster's data, for example, as a stream that is encapsulated within the 188-byte MPEG-2 Transport Stream (TS) packets most commonly used for television broadcasts.

In conventional PSIP, various service types are defined in the virtual channel table. For example, DTV signals are service type 2 and software downloads are defined as service type 5. In accord with embodiments consistent with the present invention, an NRT service type is defined as a new service type (e.g., service type 8). Hence, when the virtual channel table indicates that a service type 8 is present, the receiver can expect and look for receipt of an NRT-IT. The NRT-IT therefore defines the various parameters that might be used or needed to process and present the NRT content and the associated metadata to the viewer. It is noted that one service ID in the SMT can point to multiple items of NRT content which have varying parameters. The content information in the NRT-IT can define more stringent requirements to consume the content than that generally defined in the SMT. By way of example, the SMT may specify the support of a particular codec is required in the receiver to offer a meaningful presentation of the service, but the content definition in the NRT-IT may specify a codec with different and more stringent requirements.

The NRT-IT may contain multiple table elements including, but not limited to, content name, content ID, Distribution start/end times, playback length, content length (in terms of storage required), content types (codecs), language or languages, audio information, video information, caption service information, content advisories, genre, service information, optional encryption keys, and may contain a content URL where the content can be immediately retrieved rather than awaiting the next instance of a broadcast. The attached APPENDIX provides a detailed example of an implementation specification for implementing the NRT Information Table and defines its associated elements. This should form a part of a system specification for NRT services such as an NRT specification as is at the time of this writing being drafted by the ATSC.

FIG. 3 depicts a simplified TV receiver system 20 that is devised to receive both real time television broadcasts and NRT content. In this system a modulated RF input signal is received, tuned and demodulated at a tuner 24 to produce an ATSC output transport stream (as modified by incorporation of the NRT content as described herein). The transport stream is conventionally a bit stream flowing at a rate of 19.39 Mbps that may carry a plurality of channels of content including NRT content in 188-byte MPEG-2 compliant Transport Stream packets. This Transport Stream is demultiplexed at the demultiplexer 28 to produce program-specific information (PSI) tables (per ISO/IEC 13818-1) and PSIP tables (per ATSC A/65 PSIP) and a DSM-CC packet stream to CPU 32. For the case of conventional real time (linear) TV content, audio and video packets are supplied to an A/V decoder 36 for decoding. The decoded audio is supplied to an audio sub-system (not shown) that reproduces the audio and the video is supplied to a compositor 40 which supplies the video output to the TV' s video display circuits (also not shown).

In the alternative, content can be received as a stream of IP packets from the Internet at an IP demultiplexer 42 such that they are passed directly to CPU 32 for processing.

Depending upon the mode of operation of the display, the CPU 32, which operates in conjunction with application and operating system memory in ROM or Flash memory 44, and RAM 46 for example to supply text or graphics (e.g., as in a graphical user interface [GUI]) as generated by a graphics subsystem 50 that operates using graphics memory RAM 54 to produce graphics as overlays or the like to compositor 40. Compositor 40 combines the graphics if present with the decoded video as its video output.

For NRT files and metadata received in the transport stream, this data is routed via the CPU to RAM 46 and the content and metadata can be stored to bulk storage such as a disc drive 58. When the CPU 32 instructs the system to play a selection of NRT content, the NRT files are demultiplexed from their file wrapper (e.g., an MP4 A/V wrapper) at 60 to provide audio and video packets established according to a filter criteria to the A/V decoder 36 for ultimate presentation to the consumer.

Referring to 64 of FIG. 4, in order to provide the functionality for access, download and playback of the NRT data and content, processor 32 the IP packets received via the transport stream for support of NRT content is demultiplexed in an IP packet demultiplexing operation 68 to first separate the stream into the FLUTE file description table, the NRT file content and service and signaling information. The NRT file content is stored to the bulk storage 58 and the FLUTE file description table is processed by a FLUTE description table parser 72 to produce NRT file metadata. The service signaling channel data is processed by an NRT data parser 76 that separates the NRT metadata into 1) service map table (SMT) data that is parsed at a SMT parser 80 to produce NRT service metadata; 2) text fragment table data (TFT) that is parsed at TFT parser 84 into NRT content descriptive text; and 3) NRT-IT data that is parsed at NRT-IT parser 88 into NRT content metadata. The output of parsers 72, 80, 84 and 88 can be stored either in local RAM or Flash memory or bulk storage 58 or any combination thereof (or using any other storage mechanism). Generally, bulk storage is reserved for larger files or for additional storage when other memory is at a premium.

Many variations of the above will occur to those skilled in the art upon consideration of the present teachings. The application used by a receiver is easily devised upon consideration of the present teachings, and can be implemented in a wide variety of ways, allowing manufacturers great latitude in product differentiation while providing for NRT services consistent with a standard delivery arrangement.

Thus, in certain embodiments, a digital television receiver that receives non-real time (NRT) content has an IP demultiplexer (Demux) or a radio frequency tuner that receives a transport stream. The output transport stream contains an IP packet stream containing NRT content, a FLUTE file description table (FDT) and NRT metadata. An electronic storage medium is provided and a demultiplexer demultiplexes the IP stream of packets to produce: NRT content that is stored in the electronic storage medium, the FLUTE FDT, and NRT metadata. An FDT parser parses the FDT to produce NRT file metadata from the FLUTE FDT. An NRT metadata parser produces NRT service metadata, NRT content description text and NRT content metadata.

In certain implementations, a digital television receiver that receives non-real time (NRT) content has a radio frequency tuner that receives a radio frequency modulated channel containing a transport stream over a tuned channel and demodulates the channel to produce an output transport stream. The output transport stream contains an Internet Protocol (IP) stream of packets containing non-real time content, a FLUTE file description table (FDT) and NRT metadata. An electronic storage medium is provided. A demultiplexer demultiplexes the IP stream of packets to produce: NRT content that is stored in the electronic storage medium, the FLUTE FDT, and NRT metadata. An FDT parser parses the FDT to produce NRT file metadata from the FLUTE FDT. An NRT metadata parser produces NRT service metadata; NRT content description text and NRT content metadata.

In certain implementations, a service signaling channel contains the NRT metadata. In certain implementations, the NRT service metadata is received in a Service Map Table. In certain implementations, the NRT content description text is received in a Text Fragment Table (TFT). In certain implementations, the NRT content metadata is stored in an NRT information table (NRT-IT). In certain implementations, the output transport stream further comprises a virtual channel table (VCT), and wherein the VCT contains a service type code indicative of a virtual channel corresponding to NRT content. In certain implementations, the NRT service metadata is stored in a Service Map Table (SMT), the NRT content description text is stored in a Text Fragment Table (TFT), the NRT content metadata is stored in an NRT information table (NRT-IT), and wherein the output transport stream further comprises a virtual channel table (VCT), and wherein the VCT contains a service type code indicative of a virtual channel corresponding to NRT content. In certain implementations, the SMT signals an IP destination address and Port number that points to the FLUTE FDT, and wherein the SMT has a service ID (SID) that indexes a table entry pointing at a matching service ID in the NRT-IT. In certain implementations, the NRT-IT table has a content ID that indexes table entries in the FLUTE FDT. In certain implementations, the NRT-IT table further includes entries in the TFT. In certain implementations, the NRT-IT table includes a Playback Delay parameter that indicates an amount of time from the recovery of the first byte of the file the receiver should wait prior to beginning playback of the content. In certain implementations, the NRT-IT table includes a flag indicating whether or not the NRT file can be extracted from the broadcast stream with lower-latency or whether the receiver should prompt the user to return to view it at a later time due to longer latency, wherein lower and longer are measured with respect to one another. In certain implementations, the NRT-IT table points to a table that points to a graphical icon representation of the NRT service or content item. In certain implementations, the NRT service metadata is stored in a Service Map Table. In certain implementations, the NRT content description text is stored in a Text Fragment Table (TFT). In certain implementations, the content metadata comprises an indication that the identified content may be retrieved from an Internet-based server, and a Uniform Reference Locator (URL) that may be used to effect said retrieval.

In another implementation, a digital television receiver that receives non-real time (NRT) content has an Internet protocol (IP) receiver that receives a stream of IP packets and selects an IP subnet containing a packet stream selected as an output packet stream. The output packet stream contains non-real time content, a FLUTE file description table (FDT) and NRT metadata. An electronic storage medium is provided. A demultiplexer demultiplexes the IP packet stream to produce: NRT content that is stored in the electronic storage medium, the FLUTE FDT, and NRT metadata. An FDT parser parses the FDT to produce NRT file metadata from the FLUTE FDT. An NRT metadata parser produces NRT service metadata and NRT content metadata.

In certain implementations, a Service Signaling Channel (SSC) contains the NRT metadata. In certain implementations, the NRT service metadata is received in a Service Map Table. In certain implementations, the NRT content description text is received in a Text Fragment Table (TFT). In certain implementations, the NRT content metadata is received in an NRT information table (NRT-IT). In certain implementations, the output transport stream further comprises a virtual channel table (VCT), and wherein the VCT contains a service type code indicative of a virtual channel corresponding to NRT content. In certain implementations, the NRT service metadata is received in a Service Map Table (SMT), the NRT content description text is received in a Text Fragment Table (TFT), the NRT content metadata is received in an NRT information table (NRT-IT), and wherein the output transport stream further comprises a virtual channel table (VCT), and wherein the VCT contains a service type code indicative of a virtual channel corresponding to NRT content. In certain implementations, the SMT has an IP destination address and Port number that points to the FLUTE FDT, and wherein the SMT has a service ID (SID) that indexes a table entry pointing at a service ID in the NRT-IT. In certain implementations, the NRT-IT table has a content ID that indexes table entries in the FLUTE FDT. In certain implementations, the NRT-IT table has a content ID that indexes table entries in the FLUTE FDT. In certain implementations, the NRT-IT table further includes entries in the TFT. In certain implementations, the NRT-IT table includes a Playback Delay parameter that indicates an amount of time from the recovery of the first byte of the file the receiver should wait prior to beginning playback of the content. In certain implementations, the NRT-IT table includes a flag indicating whether or not the NRT file can be extracted from the broadcast stream with lower-latency or whether the receiver should prompt the user to return to view it at a later time due to longer latency, wherein lower and longer are measured with respect to one another. In certain implementations, the NRT-IT table points to a table that points to a graphical icon representation of the NRT service or content item. In certain implementations, the NRT service metadata is stored in a Service Map Table. In certain implementations, the NRT content description text is stored in a Text Fragment Table (TFT). In certain implementations, the content metadata comprises an indication that the identified content may be retrieved from an Internet-based server, and a Uniform Reference Locator (URL) that may be used to effect said retrieval.

Another digital television receiver that receives non-real time (NRT) content has a receiver device that receives a signal and produces an output transport stream, the output transport stream containing an Internet Protocol (IP) stream of packets containing non-real time content, a FLUTE file description table (FDT) and NRT metadata. An electronic storage medium is provided. A demultiplexer demultiplexes the IP stream of packets to produce: NRT content that is stored in the electronic storage medium, the FLUTE FDT, and NRT metadata. An FDT parser parses the FDT to produce NRT file metadata from the FLUTE FDT. An NRT metadata parser produces NRT service metadata; NRT content description text and NRT Content Metadata.

Those skilled in the art will recognize, upon consideration of the above teachings, that certain exemplary embodiments may be based upon use of a programmed processor. However, the invention is not limited to such exemplary embodiments, since other embodiments could be implemented using hardware component equivalents such as special purpose hardware and/or dedicated processors. Similarly, general purpose computers, microprocessor based computers, micro-controllers, optical computers, analog computers, dedicated processors, application specific circuits and/or dedicated hard wired logic may be used to construct alternative equivalent embodiments.

Those skilled in the art will also appreciate, upon consideration of the above teachings, that the program operations and processes and associated data used to implement certain of the embodiments described above can be implemented using disc storage as well as other forms of storage such as for example Read Only Memory (ROM) devices, Random Access Memory (RAM) devices, network memory devices, optical storage elements, magnetic storage elements, magneto-optical storage elements, flash memory, core memory and/or other equivalent volatile and non-volatile storage technologies without departing from certain embodiments of the present invention. Such alternative storage devices should be considered equivalents.

While certain illustrative embodiments have been described, it is evident that many alternatives, modifications, permutations and variations will become apparent to those skilled in the art in light of the foregoing description. 

1. A digital television receiver that receives non-real time (NRT) content, comprising in combination: a radio frequency tuner that receives a radio frequency modulated channel containing a transport stream and demodulates the channel to produce an output transport stream; the output transport stream containing an Internet Protocol (IP) stream of packets containing non-real time content, a FLUTE file description table (FDT), NRT service metadata and NRT content metadata; an electronic storage medium; a demultiplexer that demultiplexes the IP stream of packets to produce: NRT content that is stored in the electronic storage medium, the FLUTE FDT, NRT service metadata, and NRT content metadata; and an NRT metadata parser that produces NRT service metadata; NRT content description and NRT content metadata.
 2. The digital television receiver according to claim 1, where the NRT metadata parser further processes NRT content description text derived from a Text Fragment Table (TFT).
 3. The digital television receiver according to claim 2, wherein the NRT content description text is received in the Text Fragment Table (TFT).
 4. A digital television receiver that receives non-real time (NRT) content, comprising in combination: an Internet protocol (IP) receiver that receives a stream of IP packets and selects an IP subnet containing a packet stream selected as an output packet stream; the output packet stream containing non-real time content, NRT service metadata and NRT content metadata; an electronic storage medium; a demultiplexer that demultiplexes the IP packet stream to produce: NRT content that is stored in the electronic storage medium, NRT service metadata, and NRT content metadata; and an NRT metadata parser that produces NRT service metadata and NRT content metadata.
 5. The digital television receiver in accordance with claim 4, where the NRT metadata parser further processes NRT content description text derived from a Text Fragment Table (TFT).
 6. The digital television receiver according to claim 5, where the NRT content description text is received in the Text Fragment Table (TFT).
 7. The digital television receiver according to claim 4, where the output packet stream further comprises a virtual channel table (VCT), and where the VCT contains a service type code indicative of a virtual channel corresponding to NRT content.
 8. The digital television receiver according to claim 7, where the output transport stream further comprises a virtual channel table (VCT), and wherein the VCT contains a service type code indicative of a virtual channel corresponding to NRT content.
 9. The digital television receiver according to claim 4, where the digital television receiver is embodied in a television set top box.
 10. The digital television receiver according to claim 4, where the digital television receiver is embodied in a television set.
 11. A digital television receiver that receives non-real time (NRT) content, comprising in combination: a receiver device that receives a signal and produces an output transport stream, the output transport stream containing an Internet Protocol (IP) stream of packets containing non-real time content, NRT service and NRT content metadata; an electronic storage medium; a demultiplexer that demultiplexes the IP stream of packets to produce: NRT content that is stored in the electronic storage medium, NRT service metadata, and NRT content metadata; and an NRT metadata parser that produces NRT service metadata, NRT content description and NRT content metadata.
 12. The digital television receiver according to claim 11, where the NRT content description comprises text received within a Text Fragment Table (TFT).
 13. The digital television receiver according to claim 11, where the digital television receiver is embodied in a television set top box.
 14. The digital television receiver according to claim 11, where the digital television receiver is embodied in a television set.
 15. A method of receiving digital television signals, comprising tuning a radio frequency tuner to receive a radio frequency modulated channel containing a transport stream; demodulating the channel to produce an output transport stream; the output transport stream containing an Internet Protocol (IP) stream of packets containing non-real time content, a FLUTE file description table (FDT), NRT service metadata and NRT content metadata; demultiplexing the IP stream of packets to produce: NRT content that is stored in an electronic storage medium, the FLUTE FDT, NRT service metadata, and NRT content metadata; and parsing the metadata to produces NRT service metadata; NRT content description and NRT content metadata.
 16. The method according to claim 15, further comprising processing the NRT content description comprises text derived from a Text Fragment Table (TFT).
 17. The method according to claim 16, wherein the NRT content description text is received in the Text Fragment Table (TFT).
 18. The method according to claim 16, where the digital television receiver is embodied in a television set top box.
 19. The method according to claim 16, where the digital television receiver is embodied in a television set. 